VPN status: error, ip is unusable 0.0.0.0/0

I have a gateway network with a single linux gateway and a single linux client. Before today, I could connect to the gateway computer from the client machine without issue. Before today, when I executed "ip route", I would see a route for the private subnet of the gateway computer (10.3.3.0/24). I could ping or ssh into it, no problem.

Today, even after "hamachi logout; hamachi login", that route does not appear in the routing table, and I can't ping or ssh into the gateway computer. The route for 25.0.0.0/8 is still there. When I do "hamachi network xxx.xxx.xxx", I get this:

id : xxx-xxx-xxxname : MyNetworktype : Gateway

VPN status : error, ip is unusableIP address : 0.0.0.0/0

I'm guessing that error must be related to the problem? I haven't changed any configuration on the client or gateway machines.

Sorry for not including log files; they are thousands of lines long. What is the most useful "hamachi" or other commands that I could run to produce helpful log output?